KR960016032B1 - Method for setting molding condition in injection molding machine - Google Patents

Abstract

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Description

[Name of invention]

Molding condition setting method in injection molding machine

[Brief Description of Drawings]

1 is a functional block diagram showing an injection molding machine for performing a molding condition setting method according to an embodiment of the present invention,

2 is a view showing a display example of the pressure curve and the injection molding conditions according to an embodiment of the present invention;

3 is a view showing a pressure curve according to an embodiment of the present invention,

4 is a flowchart illustrating the molding condition setting process performed by the injection molding machine of FIG.

Detailed description of the invention

[Technical Field]

The present invention relates to an injection molding condition setting method in an injection molding machine for setting injection molding conditions based on accurate information displayed on a display device.

[Background]

In an injection molding machine using a screw, the fluidized injection target is sent to the front of the screw while stirring by rotation of the screw. Next, the screw is moved in the axial direction to inject the object to be injected into the mold. As a result, the mold is injected. A molded article of a predetermined shape is formed by the object to be injected.

The quality of the molded article is determined by the change over time of the pressure (injection pressure) applied to the object to be injected at the time of injection. For this reason, it is necessary to obtain the characteristic of the ideal pressure curve which shows the time-dependent change of the said injection pressure.

Therefore, conventionally, there is a method of displaying injection molding conditions for determining injection pressure or the like on the screen of a graphic display by an NC program, such as an injection molding machine shown in Japanese Patent Application Laid-Open No. 61-106219. By changing the setting of this set value, the injection molding machine changes the characteristics of the injection pressure and performs injection of the object to be injected. As with the injection molding machine shown in Japanese Patent Application Laid-Open No. 61-125830, there is a control program that displays a pressure curve indicating the characteristics of the injection pressure on the screen of the graphic display.

By the way, in the conventional injection molding machine, the injection molding condition and the pressure curve cannot be simultaneously displayed on the screen of the graphic display because they are different from the process of displaying and setting the injection molding condition and the process of displaying the pressure curve. For this reason, when the injection molding conditions are checked and the setting changes based on the characteristics of the previous pressure curve, there is a need to perform the display switching operation of the graphic display when the injection molding conditions are set and when the pressure curves are recognized. . As a result, when the injection molding condition is displayed on the graphic display, for example, it takes time for the user to set the condition, and even if the characteristic of the pressure curve changes during the setting, the change cannot be detected. For this reason, in the injection molding machine, even if the characteristic of the pressure curve changes during the setting, the injection molding conditions may be changed based on the injection molding conditions before the pressure curve changes, and the pressure curve changes accurately. There is a problem that it is impossible to change the injection molding conditions.

[Initiation of invention]

An object of the present invention is to set the injection molding conditions on the basis of the information of the pressure change over time of the precise injection target, and thus the molding conditions in the injection molding machine which can improve the operability at the time of setting the injection molding conditions. To provide a setting method.

In order to achieve the above object, the molding condition setting method of the present invention, in the injection molding machine for controlling the movement of the screw in accordance with the set injection molding conditions, and performing the injection process for injecting the fluidized injection target object, An information detection step of detecting information of pressure over time applied to the object to be injected in the injection step, a first display control step of displaying a pressure change in accordance with the information of the pressure detected in the information detection step by a display means; And a second display control step of displaying the information on the set value of the injection molding condition on the display means together with the pressure change when the display of the injection molding condition is selected, and the injection molding according to the change of the information on the displayed set value. A condition setting step of setting a condition is provided.

As described above, the present invention causes the display means to simultaneously display the pressure change over time of the object to be injected in the injection step, the setting items of the injection molding conditions, and the set value information. For this reason, it is possible to set the injection molding conditions while looking at the pressure change and the information over time of the precise object to be injected. As a result, in the present invention, the operability at the time of setting the injection molding conditions can be improved.

Best Mode for Carrying Out the Invention

In FIG. 1, resin which is an object to be injected is filled in the cylinder 10. In the cylinder 10, the screw 1 is arrange | positioned, respectively, and the screw 1 rotates by the drive of the rotating servo motor which is not shown in figure, and sends the said resin to the front of a screw, stirring. Next, the screw 1 drives the inside of the cylinder 10 in the axial direction by the driving of the injection servo motor 2, and sends resin forwarded through the nozzle 11 of the cylinder 10. Injection into the mold (12). The servo motors such as screw rotation, injection, clamp (not shown), and ejector described above are controlled by the servo circuit 103.

The pulse coder 3 is mounted on the rotation side of the injection servo motor 2, and the pulse coder 3 outputs a pulse signal corresponding to the rotation angle of the injection servo motor 2. The position at the present time of the screw 1 is detected. The output pulses from the pulse coder 3 are sequentially integrated by the counter 102, and the accumulated counter values are stored in the screw position data RAM 109 corresponding to the predetermined sampling period of the address generator 118. . Moreover, the injection pressure sensor 4 is provided in the screw 1, and the injection pressure sensor 4 detects the injection pressure of resin by the reaction force acting in the axial direction of a screw at the time of injection. The detected injection pressure is A / D-converted by the A / D converter 101, and is sequentially stored in the output data RAM 108 corresponding to the predetermined sampling period of the address generator 118 again. The address generator 118 sequentially outputs address addresses to the RAMs 108 and 109 in response to a predetermined sampling period. That is, the address generator 118 is once cleared by the injection start command of the CPU 114 for PMC inputted through the bus arbiter controller (hereinafter referred to as "BAC") 113 and the output circuit 107, and then predetermined Address addresses are sequentially output from address 0 in correspondence with the sampling cycle of. Hereinafter, the output from the address generator 118 is called a sampling command. In addition, although the injection pressure can be detected only in the injection pressure sensor 4 in this invention, like the embodiment shown in FIG. 1, the injection pressure sensors 13 and 14 are also provided in the nozzle 11 and the metal mold | die 12, respectively. The injection pressure may be selected and detected by the changeover switch 15.

The vertical control apparatus (hereinafter referred to as "NC apparatus") 100 is a microprocessor for numerical control (hereinafter referred to as "NC CPU") 112 and a programmable machine controller connected via the BAC 113. A CPU 114 for (hereinafter referred to as "PMC") is provided. The servo circuit 103 is connected to the NC CPU 112 via the servo interface 111, and at the same time, the RAM 104 and the ROM 115 are connected.

In addition to the servo interface 111, an injection servo motor 2, a pulse coder 3, and an output circuit 107 are connected to the servo circuit 103. The servo circuit 103 emits in accordance with the torque limit for controlling the output torque of the servo motor 2 for injection output from the pulse signal output from the pulse coder 3 and the output circuit 107. Drive the servo motor (2). The RAM 104 temporarily stores data used by the NC CPU 112 and the like. The ROM 115 stores a management program for the CPU 112 to control the overall operation of the injection molding machine.

The pressure data RAM 108, the screw position data RAM 109, the RAM 110, and the ROM 117 are connected to the PMC CPU 114. The RAM 110 stores an execution program for the PMC. The ROM 117 stores a sequence program and the like for controlling the sequence operation of the injection molding machine.

The shared RAM 105, the input circuit 106, and the output circuit 107 are connected to the BAC 113 via the bus 120, and at the same time, the NC CPU 112, the PMC CPU 114, and the operator panel are provided. The controller 116 is connected. The BAC 113 performs bus adjustment for the data (data such as a program) request of the NC CPU 112 and the PMC CPU 114, and outputs desired data. The operator panel controller 116 is connected to a passive data input device (hereinafter referred to as "CRT / MDI") 119 in which a CRT display device serving as a graphic display is provided. As shown in FIG. 2 and FIG. 3, the CRT / MDI 119 shows a set value of injection molding conditions, a pressure curve indicating the injection pressure over time in one injection process, and the like on the screen of the CRT display device. . In addition, the CRT / MDI 119 displays a menu for inputting various setting data and an operation target on the screen of the CRT display device, and enables menu selection for operation of various operation keys (soft key, ten key, etc.). It is configured to.

The shared RAM 105 is a nonvolatile RAM composed of a bubble memory and a CMOS memory, and has a memory section and a setting memory section. The memory unit stores NC programs for controlling each operation of the injection molding machine, and the setting memory unit stores parameters of various molding conditions such as injection, holding pressure, metering, and cylinder temperature, various setting values, macro variables, and the like. have. In the NC device 100, the PMC CPU 114 performs sequence control based on the NC program stored in the shared RAM 105, various molding conditions, and the sequence program stored in the ROM 117. The NC CPU 112 decomposes a pulse for driving the injection servo motor 2 to the servo circuit 103 through the servo interface 111 and controls the injection molding machine. Moreover, regarding these hardware structures, it is the same as that of the conventional electric injection molding machine.

Next, the sampling process of the screw position and injection pressure concerning this invention is demonstrated.

The information of the injection pressure detected by the injection pressure sensor 4 and the information of the screw position detected by the pulse coder 3 and the counter 102 are RAM 108 and 109 according to a sampling command from the address generator 118. Is stored corresponding to the common address. That is, the output of the sampling command from the address generator 118 is started at the same time as the injection start of the injection molding machine on the basis of the injection start command of the PMC CPU 114. The injection pressure and the screw position information in the latest single injection step are stored in the common addresses of the RAMs 108 and 109 corresponding to a predetermined sampling period after the injection start.

Here, the elapsed time after the start of injection based on the sampling period γ is T, the common address of the RAMs 108 and 109 is A, the injection pressure at the time of each sampling is P, the screw position is S, and the elapsed time after the start of the injection. The relationship between injection pressure and screw position versus time is illustrated in Table 1.

TABLE 1

This sampling process ends as the end of the injection, and the information stored in the RAMs 108 and 109 is held until the next injection start, and is reset at the same time as the next injection start. Then, the same sampling process is repeatedly executed.

Next, based on the flowchart art of FIG. 4, the setting method of the injection molding conditions of this embodiment is demonstrated. In this embodiment, it is assumed that various injection molding conditions are initially set in the setting memory section of the shared RAM 105, and the injection molding machine is driven and controlled according to the above conditions. The flags F1 to F3 are set in correspondence with various injection molding conditions, and are flags for selecting setting items for setting a predetermined injection molding condition. In other words, when the flags F1 to F3 are "1", the corresponding setting item is selected, and when the flags F1 to F3 are "0", the corresponding setting item is not selected. .

The operation of the setting processing of the injection molding condition is started when the setting processing is selected by the function menu key (soft key) 9 provided by the CRT / MDI 119.

When the operation of setting the injection molding condition is started, the PMC CPU 114 resets the flags F1, F2, and F3 (step S1). Then, the display of the screen of the CRT display device is switched to the display for setting the injection molding conditions, and a part of the soft keys provided by the CRT / MDI 119 is shown in FIG. It assigns as injection condition setting key 6, weighing condition setting key 7, and temperature condition setting key 8 (step S2).

The processing of steps S3 to S7 is to determine whether any one of the assigned soft keys 5 to 9 has been operated. Normally, the soft keys 5 to 9 are not operated immediately after the start of the setting processing, and therefore the judgments of steps S3 to S7 are all negative.

Therefore, the PMC CPU 114 determines whether the monitor is finished (step S8). That is, in step S8, it is determined whether or not all the injection pressure and the screw position information of the latest single injection step are sampled and stored in the data RAMs 108 and 109.

Here, when the process currently being implemented is an injection process, it means the execution of the sampling instruction of the information of injection pressure and a screw position. Therefore, the determination of step S8 is added.

The processing of step S9 to graphic display 11 determines whether the flags F1, F2, and F3 for setting item selection are reset. In the present step, all of the flags F1, F2, and F3 for setting item selection are reset, and all of the judgments of steps S9 to S11 are added. Then, the operation of the setting processing of the PMC CPU 114 is restored to step S, and the above setting processing is executed.

While the determination of steps S3 to S11 is repeatedly executed, if the end of the monitor is confirmed in step S8, the PMC CPU 114 proceeds to the process of step S12. In step S12, the PMC CPU 114 stores sampling information (information obtained by the execution of the sampling command) of the injection pressure stored in the pressure data RAM 108 and the screw stored in the screw position data RAM 109. Read the sampling information of the position. Then, the pressure curve corresponding to the sampling information of the injection pressure is graphically displayed on the screen of the CRT display device in accordance with the waveform display method selected in the last injection molding condition setting process (step S12). This graphic display area is the waveform display area shown in FIG.

Here, in the case of selecting the waveform display method indicating the relationship between the screw position and the injection pressure, the PMC CPU 114 is the horizontal axis S for the screw position and the vertical pressure P for the injection pressure. Displays the pressure curve of the Cartesian coordinate system. That is, in the present embodiment, the screw position Si and the injection pressure Pi, which are sampling information stored at the same address of the RAM 108, 109, are regarded as a pair of the Cartesian coordinate system, and points (Si, Pi) constituted by each pair are set. Plotting is performed sequentially on the waveform display area of the CRT display device to display a pressure curve indicating the relationship between the screw position and the injection pressure (see FIG. 1). In the process of setting the setting conditions of the last injection molding conditions, when the waveform display method indicating the relationship between the elapsed time after the start of injection and the injection pressure is selected, the PMC CPU 114 displays the elapsed time after the start of injection. The pressure curve of the Cartesian coordinate system whose horizontal axis T and injection pressure are the vertical axes P is displayed. That is, the elapsed time iγ corresponding to the sampling cycle after the start of injection and the injection pressure Pi for each sampling cycle are regarded as a pair of Cartesian coordinate systems, and the points iγ and Pi formed of the respective sets are defined as the waveform display area of the CRT display device. It plots sequentially and displays the pressure curve which shows the relationship of the inclination time after injection start and injection pressure (refer FIG. 2). Each waveform display method is selected corresponding to the operation of the display changeover key 5. That is, when the operator operates the display changeover key 5, the PMC CPU 114 detects the on state of the display changeover key 5 in step S3. The subprogram of the waveform display device to be executed in step S12 is designated by the operation of the waveform display switching processing. In this embodiment, there is a subprogram which executes a waveform display indicating the relationship between the screw position and the injection pressure, and a subprogram which executes the waveform display indicating the relationship between the elapsed time after the injection start and the injection pressure. In the waveform display switching processing, each subprogram is alternately designated by the on / off operation of the display switching key 5. In the waveform display switching processing, the currently designated subprogram is held until the display switching key 5 is re-operated. Therefore, in the waveform display processing immediately after the start of the injection molding condition setting process, when the display changeover key 5 is not operated, the pressure curve is displayed in accordance with the waveform display method selected in the last process of setting the injection molding condition.

In addition, when the display switching key 5 is operated immediately after starting the injection molding condition setting processing and before the waveform display processing is executed, the PMC CPU 114 has a subprogram different from the previous selection. It is determined that it is specified, and the waveform display processing based on the subprogram is executed. However, since the pressure curve is not displayed before the waveform display process is executed, the operator knows the waveform display method that is selected at this time and the waveform display method that can be selected in accordance with the operation of the display changeover key 5. Can't. Therefore, it is not very meaningful to operate the display switching key 5 before the waveform display processing is executed. However, the PMC CPU 114 can cause the CRT display to display the waveform display method selected at this point in time, or can identify the waveform display method in accordance with the operation position of the display changeover key 5. In such a case, it is effective to operate the display switching key 5 before the waveform display processing is executed.

Therefore, the PMC CPU 114 normally displays the pressure curve once on the screen of the CRT display device in accordance with the waveform display method selected under the last injection molding condition. By this, the PMC CPU 114 confirms to the operator the waveform display method selected at this time, and then selects the desired waveform display method for the operation of the display changeover key 5 as required by the operator.

In addition, the PMC CPU 114 holds the pressure curve information displayed in the waveform display area in the RAM 108 and 109 until the next injection is completed. When the next injection ends and the end of the monitor is confirmed in step 8, the PMC CPU 114 displays the pressure curve of the latest one injection process on the screen of the CRT display device in accordance with the same waveform display processing as described above. Mark it.

As a result, a waveform display area and a condition display area are provided on the screen of the CRT display device, and the pressure curve, the setting items of the injection molding condition, and the set current values thereof can be simultaneously displayed in the waveform display area and the condition setting area.

Therefore, the operator can see the pressure curve displayed on the screen of the CRT display device, and can recognize the setting item of the injection molding condition which changes to make the pressure curve an ideal curve. For this reason, when setting the injection molding conditions, the screen switching condition becomes unnecessary, and the operability of setting the injection molding conditions is improved.

Next, the operator operates a soft key of the setting item to be changed among the injection condition setting key 6, the weighing condition setting key 7, and the temperature condition setting key 8 corresponding to the setting item. When the soft key operation is performed, the PMC CPU 114 starts the display processing of the details of each setting item, the setting present value, and the processing for setting the condition.

Next, in this embodiment, the processing operation of the PMC CPU 114 when the injection condition setting key 6 is operated will be described.

The CPU 114 for PMC detects this operation in step S4, if operation of the injection condition setting key 6 is performed by an operator, while performing the determination process of said step S3-step S11 repeatedly. In the condition setting area provided on the screen of the CRT display device, the details of setting items related to the injection condition and the setting present value are displayed (step S22). In the present embodiment, in the condition setting area, the number of stages of the injection, the switching position thereof, the number of stages of holding pressure, and the retention time thereof are displayed as the details of the setting items. In the condition setting area, a numerical value (in this case, an initial value) recorded in the setting memory unit of the shared RAM 105 is displayed as the setting current value corresponding to each of the above items.

The PMC CPU 114 resets the flag for setting item selection, F2 and F3, sets the flag for setting item selection F1, and stores in RAM 110 that the processing for injection condition setting is started. (Step S23). Next, the PMC CPU 114 determines the presence or absence of a ten key input from the CRT / MDI 119 (step S24).

Here, if there is no ten key input, the processing operation of the PMC CPU 114 is restored to step S3, and the determination process from step S3 to step S9 is performed. In addition, in this step, since the flag F1 for setting item selection is already set, the PMC CPU 114 transfers to the process of step S24 after performing the discrimination process of step S9. If there is no ten key input in this step S24, the discrimination process of step S3-step S9, step S24 is repeated. In the case where the end of the monitor is confirmed in the determination processing of step S8, the pressure curve of the latest one injection process is displayed on the screen of the CRT display device in the processing of step S12, and then the process shifts to the determination processing of step S9. .

When the PMC CPU 114 repeatedly executes the above processing operation, the operator looks at the displayed pressure curve, operates the cursor movement keys of the CRT / MDI 119, and sets the condition setting area on the screen of the CRT display device. Select the desired setting item from the details of the setting items displayed on the screen, and operate the ten key to input a new setting value.

When the PMC CPU 114 detects the new setting value by ten key input in step S24, the setting current value of this setting item displayed in the condition setting area is displayed and changed to the new setting value. The PMC CPU 114 also stores the new setting value in the storage area of the setting memory section of the shared RAM 105 corresponding to the setting item, and updates the setting present value (step S25).

Thereby, in the injection process from the next time, the injection molding machine controls the injection operation on the basis of the new set present value updated in step S25. With the change of the setting of the injection condition, the characteristic of the pressure curve displayed in the waveform display area gradually changes, but as shown in steps S8 and S12, when the monitor is finished, the waveform injection range is always the latest one injection process. Pressure curve is displayed.

Thus, the operator looks at the new displayed pressure curve and determines whether the characteristic of this pressure curve is the characteristic of the ideal pressure curve. That is, the operator judges whether or not correction of the injection condition is appropriate, and if necessary, selects an arbitrary setting item by soft key and inputs a new setting value by ten key. The PMC CPU 114 updates the injection conditions again in the same manner as above with respect to the input of the new set values.

TABLE 2

Weighing conditions

In addition, when it is determined that it is necessary to correct the weighing condition, the cylinder temperature, or the like, the operator operates the weighing condition setting key 7 and the temperature condition setting key 8. When the CPU 114 for PMC detects the operation of the soft keys 7 and 8 in step S15 and step S6, it updates the process for setting weighing conditions, or the process for setting temperature conditions. The PMC CPU 114 executes the process for setting the weighing condition in steps S18 to S21 or executes the process for setting the temperature condition in steps S14 to S17. In addition, a process for setting the temperature condition is executed at the condition setting set on the screen of the CRT display device. Tables 2 and 3 show examples of setting items for weighing conditions and examples of setting items for temperature conditions displayed on the condition setting area set on the screen of the CRT display device. In addition, since the flow of these processes is substantially the same as the process for setting injection conditions already demonstrated in step S22 to step S25, detailed description is abbreviate | omitted.

TABLE 3

Temperature conditions

When the PMC CPU 114 repeats the process of setting the injection molding conditions, corrects various setting values such as the injection conditions, the metering conditions, the cylinder temperature, and the like, and obtains an ideal pressure curve, the operator can perform CRT / MDI ( The function menu key 9 of 119 is operated to select another display screen. When the function menu key 9 is operated, the PMC CPU 114 detects the operation (step S7) and ends the process of setting the injection molding condition.

Therefore, the molding condition setting method according to the present embodiment is characterized in that, when the characteristic of the pressure curve is not immediately stabilized due to the change of the setting of the cylinder temperature following the temperature change, the weighing condition (for example, screw When the characteristic of a pressure curve is not stabilized immediately by the setting change of a bag etc., even if it takes time to set molding conditions, correct | amendment of a set value can be performed correctly. This is because in the present embodiment, the pressure curve in the latest one injection process can be displayed on the screen of the CRT display.

Claims (9)

An injection molding machine which performs a movement control of a screw according to a set injection molding condition and performs an injection process for injecting a fluidized injection target object, wherein the information of time-based pressure applied to the injection target object in the injection process is The information display means for detecting, the first display control process for displaying the pressure change in accordance with the information of the pressure detected in the information detection process by the display means, and the display value of the injection molding condition when the display of the injection molding condition is selected. And a second display control step of displaying the information on the pressure change and the display means, and a condition setting step of setting the injection molding condition in accordance with the change of the information of the displayed set value. To set molding conditions The method for setting a molding condition in an injection molding machine according to claim 1, wherein in the information detecting step, information of a pressure of an object to be injected acting in the axial direction of the screw is detected as the information of the pressure. The method for setting molding conditions in an injection molding machine according to claim 1, wherein in said information detecting step, information of pressure applied to a subject object when being injected by said screw is detected as said information of said pressure. 2. The method as set forth in claim 1, wherein in said information detecting step, information of a pressure applied to an object to be injected when being filled in a mold is detected as said information of said pressure. The object to be injected according to any one of claims 1 to 4, wherein in the information detecting step, information on the pressure of the object to be injected acting in the axial direction of the screw as the information of the pressure, and the object to be injected when the screw is ejected. A method of setting a molding condition in an injection molding machine, wherein any one of the information of the pressure applied to the information or the information of the pressure applied to the object to be injected when filled in the mold is detected. The display means according to claim 1, wherein, in the first and second display control steps, the pressure change for each predetermined elapsed time from the start of injection according to the pressure information or the pressure change for each predetermined position of the moving screw is displayed on the display means. A molding condition setting method in an injection molding machine, characterized by being displayed on. 7. The display means according to claim 1 or 6, wherein the display means displays one of the specified pressure changes among the pressure change for each predetermined elapsed time from the start of injection and the pressure change for each predetermined position of the moved screw. A molding condition setting method in an injection molding machine. 2. A method according to claim 1, wherein said display means comprises a graphic display. The method according to claim 1, wherein the setting value of the injection molding condition displayed includes a plurality of injection speeds and information indicating a switching position of the injection speeds.